A preliminary rough cut of some footage of the Move the House Apartments in Southeast Portland. I took the opportunity to capture a bit of video on a windy day that offered a significant downpour that activated many of the site features. See it in action below:
Building on the previous post, the Bonneville Power Administration Green Roof went through a number of iterations in the design process, and also required the attention and on-site modification that often comes from challenging retrofits.
The existing rooftops during demolition - predominately paved with small planters which made them feel somewhat barren. Pavers were saved and re-used in the final design which saved cost and materials.
Landscape Architect’s Role The project involved working with a diverse group of stakeholders in developing the concept, as well as coordinating with multiple trade partners as part of the design-build collaborative team. The combination of technical knowledge and experience with various green roof projects allowed the team to adapt to unique site conditions while remaining conscious of project goals and overall budget constraints. Working on structure requires knowledge of multiple systems and how they interact. In this case, the GSA outlined specific goals, but left it open to the design team to come up with creative solutions that fit the overall budget. Conversely, on a typical project, we would select a system based on the unique conditions of the project.
In this case, however, the roofing system was predetermined, so it became a challenge to fit a particular system to the project parameters. This, along with integration of additional insulation to meet energy efficiency goals meant that we needed to troubleshoot conflicts between competing project goals, allowing us to maintain safe parapet heights, incorporate window-washing infrastructure, and maintain ADA accessibility at thresholds.
A typical roof level after installation, showing the transformation of the space, with seating areas located in sunny perimeters, vegetation free zones at building edges, and the pattern of bermed vegetations with rock ‘stream’.
Another particular challenge was the structural capacity of the roof. It was determined that we had the ability to berm up in certain areas of the roof, where the original planters were located. Rather than create a homogenized and monotonous pattern, the berming configuration shifts on every roof, but still falls within specific loading parameters – invisible to the naked eye. As with most projects, determining the right mix of plantings was also vital, as the conditions for each rooftop and region vary. In this case, the terraces were on the north side of the building so the conditions were more shady, with early and late sun. Using regional experience with multiple projects and microclimates – the designers developed a palette of plantings that provided diversity, habitat, stormwater management, and heat island mitigation, while providing a dynamic and beautiful amenity for the building users.
HIGHLIGHT: A Model for Energy Efficiency Until now, vegetated roofs have not been considered viable. A recent decision by the Oregon Construction Industry Energy Board, as part of the Reach Code, recognized green roofs as both an energy conservation measure and as way to help reduce urban heat island effect. The BPA project exemplifies the concept of energy efficiency.
View from east access of typical roof, highlighting the dynamic nature of the berms along with the varying textures and colors of semi-intensive plantings. Sedum cuttings quickly colonized the low areas and side slopes to provide erosion control, color, and texture, augmented by herbs and edibles like coast strawberry available at the edge for grazing by building tenants
INNOVATION: Integrated Project Delivery Another unique feature of this project is the delivery of services. There is a trend in the green roof industry towards integrated projects, and the team has responded to this by the creation of a design-build collaborative, including the roofing contractor, landscape contractor and landscape architect as a core team. Additional sub-consultants such as structural, architectural, mechanical and related trades are added to projects on an as-needed basis. The result is a simplified process, combining all of the necessary elements together in a team with proven experience working together on similar projects. Each consultant and contractor maintains a clear distinction in scope that adheres to professional responsibilities, but the process is streamlined with more clarity of communication and documentation. For this unique project the General Contractor (GC) was able to contract with one entity to provide complete design and construction services. The team also brought in structural to evaluate roofing capacity, and mechanical engineering to assist with rainwater harvesting systems.
The variety of colors and textures occupy complex vignettes that display the periodic colors and textures. The bloom of the sedum species, natives perennials with vibrant summer blooms like Oregon Sunshine, and the pink tufts of drought tolerant Armeria maritima play off the more subtle purple shades of Hidcote Lavender.
Project Name:
Bonneville Power Administration (BPA) 905 Building Green Roof Terraces
Landscape Architect:
TERRA.fluxus | Landscape + Urbanism (Portland, OR)
Client:
General Services Administration (GSA) building owner
Bonneville Power Administration (BPA) building tenant
General Contractor:
Allen Bradbury Construction (Auburn, WA)
Roofing Contractor:
Snyder Roofing of Oregon (Tigard, OR)
Landscape Contractor:
Teufel Landscape (Portland, OR)
Mechanical / Plumbing Design (Cisterns):
PAE Consulting Engineers (Portland, OR)
Last year, we prepared some graphics for the BPA 905 Building Green Roof project, to submit it for a couple of awards. While unfortunately, we didn’t get an award, the graphics are definitely worth a second look – as they tell the story of the project and some of its unique features. Here’s part one of a two part post showing the graphics and final product.
Overview The rooftop terraces in this project are part of a larger, multiple phase effort for overall building energy efficiency upgrades as part of the American Recovery and Reinvestment Act (ARRA). The owner of the facility, the General Services Administration, along with their tenant, the Bonneville Power Administration (BPA) upgraded mechanical and building systems and replaced roofing for the entire building, allowing for the retrofit of four rooftop terraces that step down along the north portion of the building.
The project consists of four separate roofs stepping up from Level 4 to Level 7 along the north façade of the building. The total area is 9,000 square feet, with 5,800 of vegetated area.
This unique retrofit project started with new roofing that replaced the existing membrane and provided a significant increase in insulation depth for energy performance that would hit the target of R-50. Atop the new insulation, areas of non-vegetated roofing are installed with cool roofing membranes to minimize heat gain. Vegetated portions were specifically designed to meet the following client-specified goals:
An enlarged view of the Level 4 rooftop, showing the configuration of pedestrian areas, seating, and access from the interior of the building. The sculptural berms and ‘river’ connects the four roof levels and reflects the different loading characteristics of the roof.
The existing terraces were predominately paved, with large planters that previously held ornamental varieties that were irrigated with domestic water supply. The spaces were described as ‘desolate’ and were used sporadically by building users, but not considered an amenity. Through the design process, the team worked with building tenants to identify the aesthetic preferences, necessary amount of seating, and overall range of planned uses for the spaces. This involvement was also expanded to include educational information, located at building entries and key areas like the cafeteria, regarding a range of vegetated roofing options, trickling down through all of the users of the building. The distinctions between extensive green roof, semi-intensive roofing, and intensive roof terrace were vital to understanding the type of project that was being planned, and managing the overall level of expectations, which led to significant support from throughout the building.
Exploded diagram showing the built up layers from roofing, insulation, paving, and green roof components on a typical level. The cisterns are fed by roof drains and pumped back up to the green roof for irrigation that requires zero potable water.
Results The project includes over 9,000 square feet of roof area over 4 different levels. Paved terraces surround sculptural berms planted with semi-intensive vegetated roof, encompassing a total of 5,800 square feet of planted area. The rooftops are oriented for views from within the building, as well as to be viewed from above. Starting at the upper level (7th Floor) a stone ‘stream’ winds through the adjacent sculptural ‘hills’, referencing the connection of the BPA to the indigenous waterways of the Pacific Northwest. The similar size of the upper roofs (5,6,7) are less uniform due to the berming and flowing nature of these elements, giving each floor a unique experience. This unifying element connects each level down to the larger (4th Floor) where it terminates into a fanned delta. The overlapping berms and waves of vegetation provide a separation of the space to avoid the fishbowl effect and allow for adjacent access to the plantings.
The dynamic quality of seasonal planting variation is captured in flowing waves of color and texture that overlap and change over the entire year.
Over thirty species of plants were included to achieve a mosaic, including small coniferous and deciduous trees, a range of shrubs, grasses, and perennials, rounded out with a mix of succulent groundcover cuttings to quickly provide soil coverage. Plantings were selected for drought tolerance, color, texture, scent, and seasonal variation. Rainwater is captured in 35,000 gallon cisterns and pumped up to each floor, giving the project, once established, net-zero potable water usage. High efficiency irrigation heads with evapotranspiration-enabled smart controllers and moisture sensors provide additional water savings by adapting to local conditions to provide only necessary supplemental water through seasonal summer drought.
A rendering of the proposed project shows the potential usable space along with the design intent. The graphics were essential for education, as well as to manage expectations of the end result that was not an extensive roof, but not a full roof garden.
Go to Part II: Implementation
Just in time for 2012, the new calendars are available from the City of Portland, Bureau of Environmental Services and their Sustainable Stormwater Management program. This annual publication shows off some of the interesting new projects built around Portland, and it was a nice surprise to see two months that included some of the recent work of TERRA.fluxus. April features a couple of recent works – in particular the Vertical Wetland project completed at Move the House, project for Urban Development Partners, with art feature by Ivan McLean and funded by Metro, that funnels roof water through Corten sculpture visible from SE Division Street.
As mentioned in the calendar:
“Disconnecting a downspout is a simple way to remove roof runoff from the combined sewer system and protect water quality, and it offers opportunities for creative ways to disconnect.”
Also in June, a nice shot of the newly planted living wall at the same project, Move the House- showcasing the idea of vegetated walls, which contribute to sustainable site design – in this case screening the very prominent trash enclosure in the center of the outdoor plaza area – adding a burst of greenery to an item that is often considered an eyesore. As mentioned in the calendar:
The office was closed the second half of September to accommodate some long-awaited travels in Europe. Journeys included London, Barcelona, Rome, and travels through Tuscany including Siena, Florence, Orvieto, and Assisi. Regular posting to resume in October!
LONDON
BARCELONA
ROME
SIENA
ROME
The observant traveler at OHSU can spot the new green roof projects from the upper floor skyways and waiting rooms… providing the ability to see these projects without any sort of public access. Took a trip up today to see how things were doing, and managed to spy both roofs… here’s some pics of the C-Wing from the 9th floor looking down to Level 4.
And also the HRC, where you can see the predominant shading as it is enveloped in surrounding structures.
And for pleasant waiting, the view from inside the MRI waiting room gives an up close and personal view of the HRC gridded configuration and blue glass stream. Not a bad spot to hang out…
I previously mentioned the design, along with ORANGEWALLstudios for the Metro Household Hazardous Waste (H2W) Green Roof project, which is slated to start construction in September. We recently project includes re-roofing of this structure, along with over 2,500 square feet of green roof on multiple roof levels (see more on the project here). We’re excited to see this project come to fruition, until then, a sneak-peek.
A pair of bookends to the main hospital building at Oregon Health+Science University (OHSU) – the HRC and C-Wing projects (see previous posts here and here) have now been installed and growing for a couple of months. Working with Snyder Roofing of Oregon and Teufel Landscape, the first of these design-build projects to go in was the C-Wing, a narrow rectangle visible from above. The pattern of pathway and linear bands of vegetation plays off the rhythm of the existing windows, and is evident in the initial established vegetation at grade, and from above.
Soon after, the Hatfield Research Center (HRC) was installed, featuring a grid pattern of different vegetation types, adapted to the mostly shade condition between buildings. The close up shot shows the blocks of planting, along with the abstract ‘stream’ of blue glass that meanders through the grid from drain outfall to drain.
This visual elements is vibrant when viewed from above, such as the adjacent patient rooms and corridors, such as this view from the 9th floor pedestrian walkway.
Under development is a project along 38th & Division in Portland, Oregon – an infill mixed-use apartment complex developed by Urban Development Partners and designed by Francis Dardis with a range of sustainable features. A few renderings of the proposed project gives you a feel for the style, which provides a modern twist along this southeast Portland street. The major features include moving an existing house to the back of the property, and a split building that spans overtop a community courtyard that drifts through the property.
The project includes permeable paving and flow-through planters to accommodate stormwater management, which is beneficial as the project is within a combined sewer overflow (CSO) area, so additional measures were taken to relieve the pressure on the City infrastructure through this development as part of the Stormwater Management Manual. The challenge in meeting all of these requirements is to avoid stormwater becoming a problem and to treat it as an opportunity. A view of the site plan shows additional features that add to the vibrancy of the project, including artwork and landscape beds integrated through the site. In addition, the project is getting additional funding from Metro to provide innovative development approaches, which added some great ideas to an already cool project.
The canopies around the perimeter of the project will include vegetated planters to soften the building edges and provide an amenity from street level as well as from units. The following sheet shows the configuration of these ‘Green Canopies’ along with their detailed specifications and locations.
Another feature is a living wall that will surround the trash enclosure area, turning what could be a difficult area into an amenity. The design will use a custom metal fabricated system of vertical trays that will hold growing media and a number of perennials and herbs to provide color and texture throughout the seasons.
On the south portion of the property, we are incorporating a number of habitat art elements, including areas for mason bees, hummingbirds and songbirds, micro-invertebrate habitat areas, and a bird-bath feature, along with interpretive information.
The habitat is closely aligned with the site plantings, which is densely configured along the south of the property and includes screening and a large flow-through planter which will include a number of habitat-friendly species that provide shelter, food, water, and other inputs to a range of insects, birds, mammals, and potentially amphibians or other species. For a small site, this concentration of planting area creates a significant patch, especially due to its adjacency to the Ivon Community Garden.
A visual matrix of species associations shows the benefits that come from the site features, and it is interesting to note how particular species are beneficial to multiple different types of habitat from invertebrates to birds and mammals. It will be fun to see the the success of the site in attracting wildlife through art and landscape as it matures.
The site is currently under construction, and additional features are being developed, so stay tuned for updates.
An exciting project that is currently getting ready for construction phase is the rehabilitation of the green screen planters at the OHSU Kohler Pavilion. This project is driven by requirements to screen the structure, which is located at the foot of the aerial tram, from view from adjacent areas. The original structure was completed in the early 2000′s, with plantings installed in around the perimeter of the structure – growing from small planters to the large screen panels offset from the parking structure walls. As you see from this photo, the plantings have never thrived, and currently offer minimal coverage of the structure.
The problems with getting vegetation established were manifold. The planters were undersized, and also suffered from drainage issues – compounded by the uppermost planters draining down into the next level, creating super-saturated conditions that did not promote good growth. Furthermore, there was a significant ‘jump’ from the planters to the metal screen (up to 24″) which meant plantings needed to grow sideways (and also be helped) from the planter prior to growing vertical. This tended to inhibit good growth, opened plants to potential damage, as well as localized plants towards the center of the planter – only covering a small strip of the exterior screen.
CONCEPT DEVELOPMENT
TERRA.fluxus was brought in to develop a retrofit of plantings with a goal of achieving significant screening coverage for the entire perimeter of the structure. The overall scale of the project was important, as though each planter was small scale, there were three levels with 21 planters on each level – making over 60 planters for the entire project. Thus a solution had to be functional, but also simple enough to be scaled and meet budget constraints.
The drainage issues were being addressed by OHUS through a retrofit to provide diversion of the existing drainage to the side of the planters – which was an important first step. Rather than merely replace plantings in these new scenario, we looked at a combination of factors to come up with a comprehensive solution that would aid in long-term project success. The main design concept became development of a ‘jump point’ to allow vegetation to easily grow from the planter and spread vertically and horizontally along the exterior screen panels. The preliminary version of the jump point used a custom-cable system and provided a 10′ wide span from each planter, significantly improving the overall coverage potential.
With the jump point in place, the vegetation was the next focal point. While there are a number of vines that are hardy in our region, many of these are deciduous varieties that would not work for this application. In addition to providing a wide span, the plants in these planters were required to climb up to 30 feet to cover each level of the structure – so vigorous evergreen materials were chosen. Clematis armandii (Evergreen Clematis) was a first choice, providing the foundation of plantings. Rather than rely on one species, we added three additional evergreen vines to each planter, including Holboellia coriacea (China Blue Vine), Gelsenium sempervirens (Carolina Jessamine), and Akebia quintana (Fiveleaf Akebia) to round out the planters, providing diversity of color, flower, and texture.
FINAL SOLUTION
The concept evolved somewhat as pricing for the cable system was too expensive when multiplied by 60+ planters, so the ‘jump point’ detail was reworked using a simpler assembly. The foundation of this concept is use of an off-the-shelf nursery product – loop-end nursery stakes – fabricated by local company Oregon Wire. These offered a hooked end, various lenghts, and were rigid enough to span distances – and were also easily anchored in the planter soil (versus having to attached to a new bracket). This reduced installation and labor costs significantly, and also provide an easy fix for future maintenance, if needed.
As construction begins, the hope is to realize the full potential of this green screen to mitigate the visual impact of the parking structure, and maximize the amount of coverage that can be attained. Due to small planters, it is unlikely that these screens will ever achieve 100% coverage, so our aim is to provide evergreen vegetation covering 60-70% of the area year round, while offering low-maintenance and a variety of colors and textures – as shown in the rendering below.
